1. Field of the Invention
The present invention relates to an image forming apparatus including a video device such as a medium playback device, and more particularly, to an image forming apparatus including a video device, which can perform on-screen display (OSD) of the image forming apparatus and the video device with the same quality or the substantially same quality.
2. Description of the Related Art
In a TV receiver and a video device such as VTR and DVD playback devices, an on-screen display (OSD) means for displaying various kinds of setting items of the device on a portion of an image display unit and allowing a user to set the items while checking the state of the device is employed. For example, in the OSD display of the DVD, the display of a chapter and a title, the switch of an aspect ratio of a screen, an angle, a stereo sound and a caption, and the state of selecting or controlling the setting items can be controlled while checking the state of the device. In addition, a display unit for the setting items need not be separately provided and the screen or the sound can be controlled while viewing a source image.
Furthermore, even in a case of separately providing the display unit, a user must view the display unit at a distant place as a monitor becomes enlarged. Accordingly, it is difficult to set the items while viewing the display unit provided in the DVD playback device. In addition, similarly, even in the TV receiver or the VTR, it is possible to set the setting items of the TV receiver and the VTR while viewing the image display unit.
Recently, a TV receiver including a video display device and a recording medium playback device, such as a combination of a TV receiver and a VTR playback device and a combination of a TV receiver and a DVD playback device, has increased. This TV receiver need not be connected to various devices and can be installed in a minimum space.
For example, in a TV receiver including a DVD playback device, the state of selecting or controlling the setting items of the TV receiver (image quality such as brightness and contrast, channel setting, time setting, and so on) is OSD-displayed on an image display unit of the TV receiver using an OSD device included in a control unit of the TV receiver. Meanwhile, the state of selecting or controlling the setting items of the DVD playback device (the display of a chapter and a title, the switch of an aspect ratio of a screen, an angle, a stereo sound and a caption, and so on) is OSD-displayed on the image display unit of the TV receiver using a OSD device included in a decode device of the DVD playback device.
Generally, in a case of displaying a source image of satellite broadcasting, ground-based broadcasting, or a DVD on the TV receiver of the video display device, image quality may be frequently changed in accordance with the atmosphere of a place or the image of the respective source. In a case of performing the OSD display using the OSD device included in the TV receiver, a constant image quality is always maintained, regardless of the image quality of the source image. Meanwhile, in a case of performing the OSD display using the OSD device of the DVD playback device, the OSD signal output from the OSD device is transmitted to a signal control unit of the TV receiver as an image signal. Accordingly, the OSD display of the DVD playback device is performed with the image quality of the source image which was displayed just before the OSD display (see JP-A-11-146288, JP-A-2002-57959 and JP-A-2002-152621).